1. Field of the Invention
The present invention relates to an imaging apparatus formed as a video camera, an imaging-signal processing method applied to the imaging apparatus, and a program executing the imaging-signal processing method, and more particularly, to a technique for correcting fluctuations of images caused by fluctuations of air.
2. Description of the Related Art
To date, when a moving image is captured by a video camera, etc., the captured image sometimes fluctuates by the influence of a fluctuation of air. That is to say, air sometimes fluctuates locally because of the difference in temperature, and thus light path is locally refracted, resulting in a local fluctuation of a captured image in a screen by that influence. In particular, when a distant view is captured using a telescope, the distance from an object of shooting to a video camera is long, and thus the light path becomes long. Accordingly, there is a problem in that the fluctuation of an image being captured caused by the fluctuation of air appears seriously, and the fluctuation becomes conspicuous.
If a captured image has a fluctuation caused by air, an adverse effect arises in the image, for example a place originally to be a line shakes and is deformed. The fluctuation itself is a problem in the case of a moving image. However, in the case of capturing a still image, if there is a fluctuation, there is a problem in that a line is bent, and the like.
Japanese Unexamined Patent Application Publication No. 2006-107457 has disclosed the detection of an object excluding an influence of a fluctuation from an image signal obtained by capturing an image using an imaging apparatus. The “fluctuation” described in this patent document corresponds to the fluctuation of air described in this specification.